Check these tips on exporting small PDF files from Illustrator. You can significantly reduce the file size using compression and other methods below and make file upload and download as fast as possible.
Exporting for print
When exporting small PDF files from Illustrator, there are many ways to reduce the file size. Lowering the resolution of the images is one of them. When you are exporting for print, you should keep the images inside the file at 300ppi. That makes the available options a bit limited compared to exporting for digital form only. Let’s have a look at the example below.
When I exported this file to PDF, it resulted in total of 40.2 MB. Basically, I just checked ‘Optimize for Fast Web View’ option and used bicubic downsampling to 300ppi. You can see the settings I’ve used below:
Time to resize!
Now, by simply unchecking the ‘Preserve Illustrator Editing Capabilities’ and ‘Create Acrobat Layers from Top-Level Layers’, I was able to reduce the PDF file size to 15.5 MB. However, bear in mind that in case of unchecking ‘Preserve Illustrator Editing Capabilities’ option, you would need to save the source file in Illustrator separately. That will enable you to edit it later. Or in other words, when opening this PDF file in Illustrator with ‘Preserve Illustrator Editing Capabilities’ option unchecked, you won’t be able to edit it. Take a look at the settings used below:
Finally, by making some further adjustments in Adobe PDF dialog and reducing the quality of the images while keeping the 300ppi, the file size was reduced drastically to 962 KB! Having started with 40.2 MB, not a bad result. How I did it is by using the Compression section of the dialog and Automatic (JPEG) compression with image quality changed set to Medium. You can play around these settings, but the ones I used can be found below:
Here is the final comparison of the file without image compression (the first two cases) and with the compression set to medium (the third case):
As you can see, there is some loss of quality in the picture. But in cases when file size is the priority and you can get away with slight compression, this is a way to go.
Exporting for digital use
When you are preparing a file for digital use, such as viewing on computer and mobile devices, reducing the file size is key. This enables fast upload and download and easy email sharing. Compared to print, resizing options are more flexible here, mainly because you don’t have to stick to 300ppi for images. Simply because print is not primary purpose of these files. I’ll use the same flyer like in the first example to demonstrate the file size reduction. In all cases, I unchecked the ‘Preserve Illustrator Editing Capabilities’ and ‘Create Acrobat Layers from Top-Level Layers’ and checked ‘Optimize for fast Web View’ option.
Image resolution of 96dpi with compression set to Medium
Resulted in PDF file size of 440 KB.
Image resolution of 96dpi with compression set to Low
Resulted in PDF file size of 361 KB.
Image resolution of 72dpi with compression set to High
Resulted in PDF file size of 415 KB.
To compare the results:
To conclude, the following settings resulted in smallest filesize: resolution of 96dpi and compression set to Low image quality. The total filesize of 361 KB.